So when I got one of these from eBay, I noticed a number on the bottom. Of course I had to know how many mold numbers there were (automated machine made - hence mold and not shop numbers).

These are rare with only seven total on eBay since ~2007. I have 4 of those that were on eBay (despite the picture showing only three). I have a no number,1, 2, 5. The ones I did not bid/buy were repeat numbers.

Ironically, TWO are on eBay as of this posting.

A cool history: According to the Baltimore Sun: "The Emerson Hotel was built -- legend has it -- because one sweltering hot afternoon in 1910 or so Capt. Isaac Emerson (the Bromo-Seltzer inventor) was dining in the Belvedere Hotel (in the pre-air conditioning days) and became so hot that he took his coat off. The management reminded him that it was a hotel rule that gentlemen had to wear coats. So the cantankerous old captain allegedly said: "Sir, you not only have lost customer, you have gained a business rival. I'll build my own hotel." And so he did."

Citro bottles were made by Captain Emerson as was the drink. He never sold Citro anywhere except the Emerson Hotel and another property of his: Brooklandview Springs.

Hence these bottles do not show up in bottle digging dumps very often, and so a lot of the bottle hobby seems unaware of their existence compared to other bottles.

I was able to (finally) contact someone called the Maryland Glass Co. expert. He has his collection in the top two floors of the Bromo Seltzer tower (another fascinating read!) in Baltimore and gives tours. I plan on meeting him and getting the tour when I travel to the Gettysburg National this summer.

He was able to tell me there are No number, and 1-5 molds. All made in various batches from 1912-1920